I have recently acquired a very clean, nice running 1967 326 2-sp AT Firebird. The car is in very good condition but came equipped with littled in the way of options (deluxe interior and power steering).

I have the opportunity to acquire a 400 engine for very little cost and am considering swapping motors.

My question is whether I'll be helping or harming the value of the car (resale value). In other words, is a standard 326 original car generally worth more or less than a "clone" 400 car? I'd probably put a TH-300 transmission and a floor shifter if I do the swap.

I guess in my mind I wouldn't consider it if it was an HO car or something but since it's a pretty run-of-the-mill V8 (stock 2 barrel carb, etc.), maybe the 400 is the way to go?

Thanks for any and all input.